A few years ago I got an old copy of the OAG from our corporate travel agent. It had seatmaps for a number of different planes and I noticed Continental's DC-10 had an interesting arrangement with a lounge down one side (this wasn't early 70s either!)

You are referring to CO's 'Pub', which started with their 747 service in the early 70s and was part of the DC-10-10 fleet when they came online in 1972. In spirit, the Pub was a coach lounge but was always located between F and coach so anyone could use it. Until 1976, it was a large area which occupied several seat rows in the front portion of the second cabin area, right behind that center entrance door. If I've got it right, in 1976 CO moved the F class galley around so that it was longitudinal, taking up 3-4 rows on the copilot's side (you can see the windows blanked out on that side). The Pub that you saw in the diagram was located on the other side of the galley, and F was reduced to four 6-across rows, in front of all this. In the Pub there was a pair of facing seats with a card table, located at the window side, a forward-facing sofa which faced the entrance area at the main door, and a bar around the galley, complete with bar stools. The overall color was orange and gold, as this was long before blue and grey became airline standard colors.
The Pub lasted well into the 1980s. I have fond memories of flying CO at spring break in 1985. It was ski season and everyone got pretty festive -- good thing they put a lav in the vicinity! At the time, CO operated a few DC-10-30s to Europe and the Pacific but to my knowledge they never had quite such an extensive lounge area. (This was long before they went crazy buying up all the DC-10-30s they could get). Right up until 1999, CO operated the DC-10-10s, and though coach seating had replaced the Pub, the longitudinal galley was still there and the cabin crew called them 'Pub Ships'.